26 



PROCEEDINGS OF THE NATIONAL MUSEUM 



" <r J> J" jrP ^ 



Structure. — The zonal lines are numerous, very close together, 

 formed in large part by diaphragms; they sometimes are trans- 

 formed into basal lamellae. The walls of the tubes are quite thick 



and formed of a large number of 

 small orbicular vesicles, arranged 

 frequently in two rows. This struc- 

 ture is more visible in tangential 

 sections, where all the small vesicles 

 are quite visible between the polygonal 

 tubes. 



Affinities. — In its zoarial form this 

 species is rather close to Ceriopora aequi- 

 pedis, but it differs in its much smaller 

 aperture (0.08 mm. and not 0.12 mm.) 

 and, in sections, in the nonmoniliform 

 zooecial walls. 



Occurrence. — Lower Cretaceous (Val- 

 angian) : Sainte-Croix (Vaud), Switzer- 



.S.N.M. 



Fig. \0.— Ceriopora parvipora, new species 

 Meridian section, X 16. Lower Creta- land (COmmon) . 

 ceous(Valangian):Sainte-Cioix, Switzer- ^ ri i. at r^nnnn t 



,au(j Cotypes. — Cat. JNo. 69867, I 



CERIOPORA NUMMULARIA, new species 



Plate 23, fig.s. 1-4 



Description. — The zoarium is free, orbicular or elliptical, lenticular, 

 convex, apparently covered over by one or two enveloping lamellae; 

 the base is somewhat concave. The tubes are little thickened; the 

 apertures are polygonal, somewhat oblique, surrounded by veiy 

 small and irregular tuberosities. 



Fig. \\.— Ceriopora nummularia, new species. Longitudinal section, X 16, exhibiting the moniliform 

 tubes with large vesicles and the zonal lines. Lower Cretaceous (Valangian): Sainte-Croix, 

 Switzerland 



Measurements. — Diameter of aperture, 0.14 mm.; diameter of 

 zoarium, 7 mm. 



Structure. — In meridian section the tubes are cylindrical, with 

 peripheral gemmation; the walls are thin and moniliform. The 

 zonal lines are little separated and formed by calcareous thicken- 

 ings. Diaphragms are rare. 



